Kevin Keegan praised Oldham after they stunned Manchester City in the FA Cup - but he felt his side contributed to their downfall at Boundary Park.
"If you play like we did and can't get back at a team like Oldham, you create misery for yourself," the boss said.
"Their keeper made some good saves but we were sloppy and paid the price.
"They worked hard for Brian and one or two of their players performed heroics but if we had applied ourselves that wouldn't have been enough."
Keegan refused to blame the windy conditions for his side's poor performance.
"Oldham played some quite good football and we did too - but there was no end-product to ours," he added..
"We had enough chances but I've said before that with the Cup the winners can laugh and the losers make their own arrangements.
"We have Crystal Palace in the Premiership next week and will have to put right what went wrong here."